Ruben Taelman

At first glance, this looks like a bug in LDflex, and I think @danielbeeke's fix is correct.

@danielbeeke This would be the location that requires implementation of this: https://github.com/comunica/comunica/blob/master/packages/actor-query-operation-path-zero-or-one/lib/ActorQueryOperationPathZeroOrOne.ts#L44 Note that path-related logic can get quite complex, so I would not recommend getting into this as your...

Related to #810.

Ah, I already see the problem. It's similar to the problem we had before indeed. Passing `this.mediatorQueryOperation` as second argument to [this call](https://github.com/comunica/comunica/blob/master/packages/actor-query-operation-leftjoin/lib/ActorQueryOperationLeftJoin.ts#L39) should fix the problem. Now that I...

@heartpunk Great!

Oh, good catch @jeswr. > The consequence of this is that calling engine.execute() should never cause blocking behavior, but simply return an iterator that will become readable once data is...

I think we _do_ need this wrapping, since `match` can not be made async, and `proxyIt` is only determined async. Unless I'm missing something @jeswr?

Sounds good!

Is this with lenient mode enabled? Because that could explain the inconsistent query results if errors were to occur.

And do you see any warnings from the Comunica logger showing up when executing this in lenient mode?